JP4608318B2 - Rhenium-containing supported catalyst and method for hydrogenating carbonyl compounds in liquid phase using the catalyst - Google Patents

Abstract

A supported rhenium containing catalyst (I) contains a further metal from Group 8 or 1b, preferably ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os,) iridium (Ir), platinum (Pt), copper (Cu), silver (Ag) or cobalt (Co) in the form of at least one bimetallic precursor compound applied to the support. An Independent claim is also included for a process for the production of mixtures of tetrahydrofuran and gamma-butyrolactone by catalytic hydrogenation of carbonyl compounds using the catalyst (I).

Description

  The present invention relates to a process for hydrogenating a compound having a carbonyl group in a liquid phase over a rhenium-containing supported catalyst containing at least one other active metal applied together with rhenium in the form of a bimetallic compound. About.

  Industrial hydrogenation of compounds having carbonyl groups using hydrogen over rhenium-containing catalysts such as aldehydes, ketones, carboxylic acids, carboxylic anhydrides has been known for a long time.

  For example, DE-A 100 09 817 describes a rhenium-containing supported catalyst in which non-oxidatively pretreated activated carbon is used as the support material. The catalyst additionally contains another transition metal, in particular a platinum group metal, in order to increase the catalytic activity. Rhenium and another transition metal are then applied on the support in the form of separate or together solutions of their respective salts. The hydrogenation described leads to alcohols as the main product.

  DE-A 2 519 817 discloses a catalyst which contains simultaneously elements VII and VIII of the periodic table of elements. A rhenium-containing supported catalyst additionally containing platinum or palladium is preferred. These catalysts contain in particular rhenium and palladium, which are preferably applied simultaneously on the support according to the examples in the course of the catalyst production. According to the disclosure of DE-A 2 519 817, it is also possible to first apply the palladium compound onto the support. The activity of the supported palladium-rhenium-catalyst in the hydrogenation of compounds with carbonyl groups to alcohols is so small that the simultaneous application of high pressure and high temperature of 215 to 230 ° C is required. The implementation of hydrogenation at high pressures and temperatures is not very economical, constrained by high energy costs and material costs. Moreover, the corrosivity of the carboxylic acid solution is particularly increased under these conditions.

EP-A 1 112 776 discloses a process for hydrogenating C ₄ -dicarboxylic acids, their anhydrides or esters using a catalyst in which the rhenium component is distributed very uniformly on the support material. is there. However, since the additionally present palladium component exhibits a clear shell profile (Schalenprofil), the synergistic effect of possibly forming a phase composed of two or more metals is only used to a limited extent. Absent. Using the described catalyst, γ-butyrolactone with good selectivity is formed. However, the product mixture contains only traces of THF.

  The object of the present invention is to provide a catalyst for hydrogenating a carbonyl compound and, in the use of this catalyst, in particular, almost all of optionally substituted γ-butyrolactone (hereinafter “GBL”) and tetrahydrofuran (hereinafter “THF”). Carbonyl compounds, in particular dicarboxylic acids, such as maleic acid and / or succinic acid, which are capable of producing mixtures having the same proportions and which can be produced with good conversion with good overall selectivity Or providing a method of hydrogenating their anhydrides or esters.

  The problem is that of carbonyl compounds such as dicarboxylic acids and / or their derivatives, in particular maleic acid and / or succinic acid, their anhydrides and / or esters, in particular of γ-butyrolactone and tetrahydrofuran which may be substituted. Solved by a rhenium-containing supported catalyst for hydrogenation to a mixture, said catalyst comprising at least one other metal of group VIII or Ib of the periodic table of rhenium and elements, in particular ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt), copper (Cu), silver (Ag) or cobalt (Co) is applied onto the support in the form of at least one bimetallic precursor compound. It is characterized by

  A bimetallic precursor compound is understood here to be a compound having a rhenium atom or rhenium cation and an atom or cation of a group VIII or Ib metal of the periodic table of elements.

Preferably the perrhenate-double salt as bimetal precursor compound, particularly preferably the general formula I
[Me _a (NH ₃ ) _b (OH) _c ] (ReO ₄ ) _d · eH ₂ O (I)
Or a mixture thereof, wherein Me is a metal of group VIII and Ib of the periodic table of elements, particularly Ru (ruthenium), Rh (rhodium), Pd (palladium), Os (osmium), Ir (iridium), Pt (platinum), Cu (copper), Ni (nickel), Ag (silver) or Co (cobalt) is represented, a is 1 or 2, b is an integer of 1-8, c is an integer of 0 to 5, d is 2, 3 or 4, and e is an integer of 0 to 12.

  A double salt is a mixed crystal of two salts. The anions and cations of the ionic crystal can be replaced by other cations and anions without changing the crystal structure type. If the ion pairs that are representative of each other are not purely random and are arranged in the ion lattice according to a particular distribution scheme, double salts are formed. The production of such double salts is known per se and is described, for example, by Pechenyuk, S.I., Kuznetsov, V.Y., Popova, R.A., Zalkind, O.A. in Zh. Neorg. Khim. 24 (1979) 3306.

  In accordance with the present invention, it has been found that the use of these double salts to apply the catalytically active component onto the support achieves a uniform distribution of all catalytically active metals.

Particularly preferably, Pd (NH ₃ ) ₄ (ReO ₄ ) ₂ and / or Pt (NH ₃ ) ₄ (ReO ₄ ) ₂ is used as the bimetallic precursor compound.

  All known support materials are considered for the production of hydrogenation catalysts as support materials. Preferred are silicon oxide, aluminum oxide, titanium dioxide, zirconium dioxide, magnesium oxide, optionally pretreated activated carbon, graphitic carbon support, nitride, silicide, carbide or boride. The pretreatment mentioned may be an oxidative pretreatment, as described for example in EP-A 848 991. Preferably, a support consisting of optionally pretreated activated carbon is used.

  Rhenium (Re, calculated as metal) and the other metals of group VIII or Ib of the periodic table are each 0.03 to 30% by weight, preferably 1 to 12% by weight, based on the total catalyst consisting of support and active material. %, Particularly preferably 2 to 5% by weight.

  Additional elements may be present on the catalyst. Illustrative examples include Zn (zinc), Sn (tin), Au (gold), Fe (iron), Mn (manganese), Cr (chromium), Mo (molybdenum), W (tungsten) and V (vanadium). Can do. Similarly, elements VII, VIII or Ib of the periodic table of elements such as rhenium (Re), platinum (Pt), ruthenium (Ru), silver (Ag) and palladium (Pd) are additionally present. It's okay. These elements essentially modify the catalyst in terms of activity and selectivity (hydrocracking products), but not essential. Their mass ratio to rhenium may be from 0 to 100, preferably from 0.5 to 30, particularly preferably from 0.1 to 5. Preferably the catalyst according to the invention is especially chromium-free.

  The application of rhenium as an active ingredient and further a Group VIII or Ib metal of the Periodic Table of Elements is dissolved in each of the aqueous, alcoholic or other organic solvents produced in one or more steps. Impregnation of a bimetallic precursor compound, particularly preferably a double salt of the general formula I, into a solution in an aqueous or alcoholic solution on a support in one or more steps, in particular Preferably it can be carried out by equilibrium adsorption of double salts of the general formula I. In these processes, the active ingredients are applied simultaneously and uniformly on the support material. There is in each case a drying step to remove the solvent between the individual impregnation steps and the equilibrium adsorption step. Preferably, the active ingredient is applied by impregnation in an aqueous salt solution in one step.

  In order to remove the solvent after the impregnation step or the equilibrium adsorption step, the impregnated catalyst is dried. In this case, the drying temperature is 30 to 350 ° C., preferably 40 to 280 ° C., particularly preferably 50 to 150 ° C.

  The active component is distributed particularly uniformly on the support of the catalyst according to the invention, in particular the intensity ratio of rhenium to group VIII or group Ib metal (Me) of the periodic table of elements for all catalyst particles is statistically averaged. With respect to the value, a deviation of less than 10 factors at an analysis point above 99.9%, preferably a deviation of less than 5 factors at 98% of the analysis points on the catalyst surface and particularly preferably 2 at 80% of the analysis points. With a deviation of less than one factor.

  This factor was measured using SEM-EDX (scanning electron microscope-energy dispersive X-ray spectroscopy). Said method is known per se and is described, for example, in Ulmanns Encylopedia of Industrial Chemistry 6th edition 2000 Electronic Release.

  The catalysts are usually activated before their use. This activation can be performed by applying a reducing gas atmosphere to the catalyst. Activation with hydrogen is preferably used. In this case, the activation temperature is usually 100 to 500 ° C., preferably 130 to 400 ° C., particularly preferably 150 to 400 ° C. An alternative reduction method is the reduction of the metal component by contact with a liquid reducing agent such as hydrazine, formaldehyde or sodium formate. In this case, the liquid reducing agent is usually contacted at a temperature of 10 to 100 ° C. Contact at a temperature of 20 to 80 ° C. is particularly preferred.

  The hydrogenation is usually carried out at 110 to 250 ° C, preferably 150 to 250 ° C. The hydrogenation is usually carried out at a reaction pressure of 5 to 220 bar, preferably 40 to 150 bar. Hydrogenation is carried out in the liquid phase, preferably in a fixed bed.

As starting materials for the hydrogenation, carbonyl compounds which may additionally have C—C—double or triple bonds are generally suitable. Examples of aldehydes are propionaldehyde, butyraldehydes, crotonaldehyde, ethylhexanal, nonanal and glucose. Examples of carboxylic acids are succinic acid, fumaric acid and maleic acid. As esters, the esters of the acids mentioned can be mentioned, for example, as methyl-, ethyl-, propyl- or butyl esters, and also lactones such as γ-butyrolactone, δ-valerolactone or caprolactone can be used. In addition, anhydrides such as succinic anhydride or maleic anhydride can be used. Preferred starting materials are C ₄ -dicarboxylic acids and / or their derivatives, particularly preferably succinic acid, maleic acid, succinic anhydride, maleic anhydride and esters of these acids. Of course, mixtures of aldehydes, carboxylic acids, esters, anhydrides and / or lactones, preferably mixtures of carboxylic acids, can also be used.

  The compound to be hydrogenated can be hydrogenated in bulk or in solution. As the solvent, for example, one of the hydrogenation products itself is conceivable, or substances such as alcohols, for example methanol, ethanol, propanol or butanol are used, and ethers such as THF or ethylene glycol ether or γ-butyrolactone are used. Is suitable. A preferred solvent is water, especially in the case of hydrogenation of carboxylic acids.

  Hydrogenation can be carried out in the liquid phase in one or multiple stages. Suspension as well as fixed bed operation are possible in the liquid phase. In the case of an exothermic reaction, heat can be extracted by an external coolant (eg, a tubular reactor). Furthermore, evaporative cooling in the reactor is possible, especially when hydrogenated without product return. In the case of product return, a cooler in the return flow can be considered.

  The method according to the invention is illustrated on the basis of the following example.

Measurement of Strength Factor Using SEM-EDX The strength (corresponding to content) of rhenium and palladium was measured using a SEM-EDX spectrometer of type Philips ESEM-XL30-FG equipped with an EDX probe. The analysis voltage was 30 KV. The particles were divided in preparation so that a clean cut surface was obtained. Their Pd and Re contents were examined using SEM-EDX at a step of 15 μm each exceeding 300 μm from the cut surface. The ratio of Pd and Re intensity can be calculated at each measurement point.

Example 1
15.83 g of Pd (NO ₃ ) ₂ was mixed with 8 g of 25% NH ₃ solution and mixed with 8.66 g of NH ₄ ReO _{4 in} 98 g of water. The compound Pd (NO ₃ ) ₂ (ReO ₄ ) ₂ was crystallized out. The product obtained by filtration was washed with water and dried.

Example 2: Catalyst A
1.11 g of the Pd—Re salt prepared according to Example 1 was dissolved in 20 g of water at 80 ° C. 30 g of activated carbon support (Degussa AG, Duesseldorf Degussa 180) was immersed in a solution of Pd-Re salt at 70 ° C. The catalyst was then dried at 120 ° C. in nitrogen (N ₂ ) 100 Nl / h. Subsequently, it was reduced with N ₂ (100 Nl / h) containing 0.5% of hydrogen (H ₂ ) at the same temperature for 30 min and at 200 ° C. for 30 min. Subsequently, the amount of hydrogen was increased to 5% for 1 hour and further to 100% for 2 hours. Thereafter, the temperature was set to 400 ° C., and the flow rate was increased to 3000 L / h of H ₂ . The heating rate was 5 ° C./min in each case. Finally, the catalyst 7h at room temperature after cooling in N _2, was passivated in 5% air in N _2. The catalyst contained 0.5 wt% Pd and 2 wt% Re.

Example 3
1.11 g of Pd—Re salt was dissolved in 130 g of water at 40 ° C. 10 g of this solution was applied on 30 g of activated carbon support (Degussa 180) with stirring. The catalyst was then dried at 120 ° C. for 1 h. After the water washing step, the soaking and drying procedure was repeated until the entire solution was applied onto the carrier. The catalyst was subsequently dried and reduced analogously to Example 2. The catalyst contained 0.5 wt% Pd and 2 wt% Re.

Example 4
20 g of Catalyst A was charged into a tubular reactor and rinsed with N ₂ (240 Nl / h) at atmospheric pressure and 150 ° C. for 2 h. Subsequently 5% H ₂ was mixed and after 2 hours the temperature was increased to 200 ° C. and held overnight. After switching to a 50% H ₂ —N ₂ mixture, the temperature was increased to 230 ° C. for 1 h and finally reduced in pure H ₂ 120 Nl / h for an additional hour. Finally, the pressure was increased to 40 bar. Using this activated catalyst A, succinic anhydride (BSA) metered in as a 20 wt% solution in γ-butyrolactone in an amount of 6.06 g / h was hydrogenated in continuous operation at 235 ° C. and 40 bar. did. The molar ratio H ₂ : BSA was 35. A product yield of 81% (tetrahydrofuran (THF) 39% and γ-butyrolactone 35%) was achieved with 91% conversion.

Comparative Example 1: Catalyst V1
60 g of activated carbon carrier (Degussa 180) pre-moistened with water containing 0.78 g of Pd (NO ₃ ) ₂ 2H ₂ O and 1.52 g of HReO ₄ (72.8 mass% solution) in 20 ml of water with stirring Soaking at room temperature. Subsequently, the catalyst was treated analogously to the drying and reduction described in Example 2 for Catalyst A. The catalyst contained 0.5% by weight of palladium and 2% by weight of rhenium.

Comparative Example 2:
20 g of catalyst V1 was attached to a tubular reactor similar to the example and activated similar to example 5. Using this activated catalyst A, succinic anhydride (BSA) metered in a quantity of 5.94 g / h as a 20% by weight solution in γ-butyrolactone was hydrogenated in continuous operation at 235 ° C. and 40 bar. did. The molar ratio H ₂ : BSA was 35. 80% conversion resulted in a 77% product yield (tetrahydrofuran (THF) 9% and γ-butyrolactone 53%).

Claims (8)

At least one other metal represented by rhenium and metal Me is of the general formula (I)
[Me _a (NH ₃ ) _b (OH) _c ] (ReO ₄ ) _d · eH ₂ O (I)
In at least one perrhenate shown - double salt are used in the form of a metal Me in that case represents a R u, Rh, Pd, Os , Ir or P t, a is 1 or 2 , B represents an integer from 1 to 8, c represents an integer from 0 to 5, d represents 2, 3 or 4, and e represents an integer from 0 to 12, on a support as a bimetallic precursor compound. A rhenium-containing supported catalyst for producing a mixture of tetrahydrofuran and γ-butyrolactone by catalytic hydrogenation of a carbonyl compound , characterized in that it is applied. The rhenium-containing supported catalyst according to claim 1, wherein Pd (NH ₃ ) ₄ (ReO ₄ ) ₂ and / or Pt (NH ₃ ) ₄ (ReO ₄ ) ₂ is used as the bimetallic precursor compound. The rhenium-containing supported catalyst according to any one of claims 1 and 2, wherein rhenium and metal Me are present in an amount of 0.03 to 30% by mass, respectively, based on the total catalyst. 4. The rhenium-containing content according to claim 1, wherein the ratio of rhenium to metal Me for all catalyst particles, as measured by electron microscopy, has a factor deviation of less than 5 at 98% of the analysis points. Supported catalyst. Characterized by using the catalyst of any one of claims 1 to 4, a method for producing a mixture of tetrahydrofuran and γ- butyrolactone Ri by the catalytic hydrogenation of carbonyl compounds.   6. The process according to claim 5, wherein the carbonyl compound is selected from aldehydes, carboxylic acids, esters, anhydrides and / or lactones. The carbonyl compounds, maleic acid, fumaric acid, succinic acid, or their esters or selected from anhydrides such method of claim 6 wherein. The hydrogenation is carried out at a temperature in the range of pressure and 110 to 250 ° C. in the range from 5~220bar over a catalyst that is fixed arranged in the liquid phase, in any one of claims 5 to 7 Method.